1. Field of the Invention
The present invention relates to an electrical connector assembly for electrically connecting an electronic package such as a central processing unit (CPU) with a circuit substrate such as a printed circuit board (PCB), and particularly to a land grid array (LGA) connector assembly having a fastening device for securing the CPU therein.
2. Description of the Prior Art
FIG. 5 shows a conventional land grid array (LGA) connector assembly for electrically connecting an LGA central processing unit (CPU) (not shown) with a printed circuit board (PCB) 8. Also referring to FIG. 6, the LGA connector assembly comprises a fastening device 9 mounted on the PCB 8, and a socket 6 received in the fastening device 9. The fastening device 9 comprises a rectangular frame 91, and a lever 93 and a metal clip 92 respectively pivotally mounted on two opposite sides of the frame 91. The frame 91 comprises a pair of lever cams 911 at an end thereof, a rectangular cavity in a middle thereof for receiving the socket 6 therein, and a pair of mounting slots 913 at an opposite end thereof. Each lever cam 911 defines a guiding groove 912 therethrough. The lever 93 has a pair of locating portions 931 movably received in the guiding grooves 912 of the frame 91, an offset driving portion 933 between the locating portions 931, and a handle portion 932 extending perpendicularly from an end of one of the location portions 931. The metal clip 92 comprises a securing hook 921 at a free end thereof, and a pair of mounting portions 922 at an opposite end thereof. The mounting portions 922 are pivotally engaged with the mounting slots 913 of the frame 91 by a pair of fasteners such as pins 923, respectively.
In use, the clip 92 is firstly oriented perpendicularly to the frame 91, with the locating portions 931 of the lever 93 located at respective bottoms of the guiding grooves 912 of the frame 91, and the driving portion 933 disposed above the locating portions 931. The CPU is attached on the socket 6, and a copper plate (not shown) which functions as a heat dissipation device is attached on the CPU. Then the clip 92 is rotated down to a substantially horizontal position. The handle portion 932 of the lever 93 is rotated from a horizontal position outside the frame 91 upwardly and toward the frame 91, with the locating portions 931 pivoting in the bottoms of the guiding grooves 912. The driving portion 933 reaches the securing hook 921 of the clip 92, and drives the securing hook 921 downwardly. At the same time, the locating portions 931 begin to slide upwardly along the guiding grooves 912 from the bottoms thereof. The locating portions 931 reach respective tops of the guiding grooves 912, with the driving portion 933 being located under the locating portions 931 and firmly pressing down on the securing hook 921. Thus the clip 92 firmly presses the copper plate and the CPU on the socket 6, and the CPU is electrically connected with the PCB.
Conversely, when the handle portion 932 of the lever 93 is rotated up and away from the frame 91, the driving portion 933 of the lever 93 gradually moves from the securing hook 921, and the locating portions 931 progressively move back downwardly along the guiding grooves 912. Once the locating portions have reached the bottoms of the guiding grooves 912, the clip 92 is rotated upwardly to be perpendicular to the frame 91. Then the copper plate and the CPU can be easily taken out from the LGA connector assembly. This may be done, for example, when the CPU is to be replaced by a new higher-speed CPU.
However, as can be seen from FIG. 6, other components such as a retention module 7 are also mounted on the PCB 8 around the LGA connector assembly. The retention module 7 supports a heat sink (not shown) and/or a fan (not shown). During the above-described operations of the lever 93 and the clip 92, the lever 93 is liable to be encumbered by the retention module 7. In particular, the handle portion 932 may not be able to be fully rotated to the horizontal position outside the frame 91. In such case, the securing hook 921 of the clip 92 may not be able to be released from the driving portion 933, and so the clip 92 may not be able to be rotated upwardly. Accordingly, the copper plate and the CPU cannot be taken out from the fastening device 9.
In view of the above, a new LGA connector assembly that overcomes the above-mentioned disadvantages is desired.
Accordingly, an object of the present invention is to provide an electrical connector assembly such as a land grid array (LGA) connector assembly for electrically connecting an electronic package such as an LGA central processing unit (CPU) with a circuit substrate such as a printed circuit board (PCB), whereby the connector assembly comprises a fastening device having reliable operation unencumbered by other components on the PCB.
To achieve the above-mentioned object, an LGA connector assembly in accordance with a preferred embodiment of the present invention comprises a fastening device mounted on a PCB, and a socket received in the fastening device. The fastening device comprises a rectangular frame, and a lever and a metal clip respectively pivotally mounted to two opposite sides of the frame. The frame comprises a lever cam in a middle of an end thereof. The lever cam defines a locating slot therethough, and comprises a pair of screw surfaces. The clip comprises a securing portion at a free end thereof. A rectangular opening is defined in the securing portion. The lever has a locating portion received in the locating slot of the frame, an L-shaped driving portion extending from an end of the locating portion, and a handle portion extending perpendicularly from an opposite end of the locating portion. In use, the driving portion of the lever is rotated to enter the opening of the securing portion for engaging firmly with the securing portion in the opening, with a CPU pressed on the socket. During rotating the lever, the lever is unencumbered by other components, such as a retention module, on the PCB.